The washing machine is an appliance that is commonly found in residential and commercial settings and which typically uses water to properly clean articles such as e.g., clothes, linens, towels, and other machine washable items. A detergent, generally one that contains surfactants and possibly brighteners as well, is added to the water for cleaning. A fabric softener may be used during a rinse cycle for purposes of softening the washed articles, controlling static cling, and adding a scent to the articles.
Washing machines can be equipped with fluid dispensers that automatically add detergent and/or fabric softener to a load of laundry articles at appropriate time(s) during the operation of the appliance. This option can be popular with users who do not want to manually measure and add detergent and/or fabric softener. The fluid dispenser typically includes a container that stores a limited quantity of detergent or fabric dispenser. Tubing connects the container with the wash tub and a pump or other mechanism is provided for causing fluid to exit the container and enter the wash tub.
Eventually, through operation of the washing machine, the contents of the fluid dispenser will be depleted and must be refilled. The user may be able to monitor the level of fluid in a machine by a visual inspection depending upon the particular construction of the washing machine. Alternatively, some machines have been equipped with a level sensor that uses e.g., the conductivity of the detergent or fabric softener to determine when the fluid level is below a certain level.
The use of such level sensors has certain limitations. These sensors can only determine whether fluid is present at the location where the level sensor is placed. For that reason, the level sensor is typically placed at or near the bottom of the fluid container. As a result, the level sensor cannot determine e.g., whether the container is completely full or simply at a level just at or above the sensor. As such, the user is provided with very limited advance notification of when the container will be empty. While multiple level sensors could be employed at various heights within the container, such would increase the complexity and cost of the washing machine and require a level sensor at each height in the container for which a notification is desired.
Another problem that can sometimes occur in the operation of a washing machine is an imbalance in the article load within the wash basket. More particularly, during the operation of a washing machine, particularly during spin cycles, the machine can sometimes experience an extreme vibration. Typically, this event is due to different shapes and densities of the clothing or objects that are being washed which, after the washing cycle and draining of the washing basket, can stick together and cause differences in the center of mass inside the wash basket. The vibration problem can also be caused by the introduction of relatively heavier objects into the washing basket such as e.g., shoes. By way of example, after the washing cycle and draining of the washing liquid from the basket, the shoes may be located on the same side of the washing basket or in a manner that causes the center of mass of the combined washing basket and articles (such as the shoes, clothes, and other items being washed) to be off center. As the wash basket is rotated, particularly at high speeds, the off centering and centrifugal forces create an imbalance causing the wash basket to wobble as it spins—even colliding with the wash tub in an extreme case. In turn, this imbalance can generate undesired strain in the washing machine components, an undesirable level of noise, and/or “walking” of the appliance. In an extreme or prolonged situation, the imbalance created by the excessive vibration can also wear-out and damage the washing machine components.
Accordingly, a washing machine that can provide for a more accurate detection and reporting of amount of fluid left in a dispenser would be useful. More particularly, a washing machine that can report the amount of detergent and/or fabric softener in one or more fluid dispensers at substantially all levels of such fluid would be beneficial. Such a machine that can report an out of balance condition during the operation of the washing machine would also be useful.